birding

The Eurasian Roller in Austria

MTI

BalzfÃ¼tterung Blauracken PÃ¤rchen

The Eurasian Roller was, up until about 50 years ago, a common breeding species in the farming areas of both western and eastern Styria (Steiermark). Most frequently seen sitting along telephone lines or on hay stacks, this dove-sized little predator is striking in its turquoise coloration. In 1950, it was estimated that there were about 500 pairs in Styria alone. At the end of the sixties, the species was to be found in southern Carinthia (KÃ¤rnten), Styria, southern Burgenland, with a few pairs in Lower Austria (around Seewinkel am Neusidlersee). The species continued its decline into the seventies and by the end of the decade had disappeared from all but a small area in south-eastern Styria, between Feldbach, Bad Radkersburg and Leibnitz. By the mid-1980s, this population had been reduced to only 15 breeding pairs.

Some attribute the speciesâ€™ decline to climate changes in central Europe, but the majority of ornithologists believe that â€“ as with many other large insectivores â€“ the change in land-use patterns and dynamics dealt the worst blow to the species. Specifically, areas that used to be farmed with a variety of crops and fallow land have been increasingly converted into expansive corn monocultures. Without the natural meadows and fields, the insect eaters are left with a very poor habitat for the dietary quantity and variety they require.

Since the end of the eighties, the population size has remained at about 10-15 pairs but the breeding range of the species has shrunk to only about 20-30 kmÂ². Shortly after the accession to the European Union, the area was formally protected as a Natura2000 protected area. As a result, the remaining meadows and fields have been protected and much agricultural land has been returned to its natural state. In addition, farmers who are part of the programme are required to place perches in their field from which the Eurasian Rollers can hunt.

Eurasian Rollers are cavity nesters and, obviously, need access to cavities within their breeding areas. The rollers in Styria have a particular preference for old Green Woodpecker cavities, 5-10m above the ground, in deciduous trees along the forest edge, in a riparian zone, along fences, or in avenues of trees. In the past five years, a considerable effort has been made to decrease the amount of nest-site competition (with, for example, Starlings) by erecting a total of about 60 nest boxes. The nest boxes seem to have been successful and a number of roller pairs have used them so far: nine in 2004, six in 2005, 13 in 2006 and 10 in 2007. This is about 70-80% of the entire Eurasian Roller breeding population in the area!

An ornithological working group (led by Peter Sackl and Michael Tiefenbach) was founded in 2001 to investigate various aspects of the Eurasian Roller population in Austria, including:

The monitoring of the roller population and nesting

Recording of land cover and land use/habitat

The study of roller space and habitat utilization

Study of roller prey selection and diet choice

Our results have shown that the rollers select habitats with greater structural heterogeneity, greater proportion of non-cultivated fallow fields/meadows, together with a large selection of potential hunting posts in the form of bushes, trees, telephone lines etc. This suggest that it is not only the availability of natural fields during and after the breeding season that is important, but also the management of the fields. The Eurasian Roller relies on open habitats and the regular mowing or trimming of the field can help to maintain feeding sites. They favour edges where two habitats meet and where a variety of vegetation heights and types provide a greater diversity both structurally and â€“ more importantly â€“ of prey items. After the young have fledged, the rollers will tend to expand their feeding ranges into neighbouring areas.

Systematic monitoring of nest sites has revealed that the weather has a dramatic effect on the reproduction and reproductive success of the rollers. Exceptionally long and poor weather conditions can cause high nestling mortality. In addition, the use of artificial nest boxes provides extra non-natural threats such as being potentially easier for predators to access than natural cavities.We still do not know whether our efforts over the last few years have been successful in securing the future for the population, but ringing studies have suggested that this population appears to be completely isolated from neighbouring populations and there is no (or very little) genetic flow in to the Austrian population. What we do know is that without dedicated monitoring, study and protection of the Eurasian Roller, the last central European population of the species will be doomed. How long the Eurasian Roller can last against civilizationâ€™s constant onslaught remains in the balance and will only be tipped in its favour when we start to take responsibility for how we treat Mother Earth and realize how our actions affect the species we share her with.